Aspects of this disclosure relate generally to telecommunications, and more particularly to techniques for dynamic uplink antenna port management.
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single-carrier frequency division multiple access (SC-FDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. For example, 5G new radio (NR) communications technology is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations. In an aspect, 5G communications technology includes enhanced mobile broadband addressing human-centric use cases for access to multimedia content, services and data; ultra-reliable-low latency communications (URLLC) with strict requirements, especially in terms of latency and reliability; and massive machine type communications for a very large number of connected devices and typically transmitting a relatively low volume of non-delay-sensitive information. As the demand for mobile broadband access continues to increase, however, there exists a need for further improvements in 5G communications technology and beyond. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
In conventional systems, a user equipment (UE) may include a large number of antennas (e.g., 4 or 8 antennas), especially at high carrier frequencies such as, but not limited to, millimeter wave. In conventional systems, the UE can transmit reference signals, control signals and data signals in accordance with one or more precoding schemes known to the UE, e.g., based on one or more previously connections to a base station. These previously used precoding scheme(s) may be outdated because conditions may have changed between a previous connection and a current connection. Depending on the form factor of the UE and the usage pattern of the user of the UE, some of the antennas of the UE may have a different extent of blocking than other antennas. For example, some antennas of the UE may be blocked by a hand of the user or some other obstacle in an environment of the UE. Further, different antennas of the UE may be located at different positions on the UE which may result in a permanent imbalance between the different antennas in terms of signal strength. As a result, each antenna of the UE may have an imbalance in channel quality between the antenna and a base station. Moreover, certain beamforming directions may be blocked due to the presence of an obstacle in the environment of the UE. The base station may not be aware of such antenna imbalances or obstacle(s) and therefore, the base station may not select an optimal precoding scheme for uplink or downlink transmissions. Thus, improvements in selecting precoding schemes for uplink and downlink transmissions are desired.